Door stop



Aug. 18, 1959 L. c. JOHNS-ON 2,899,703

DOOR'STOP Filed Jan. 13, 1955 2 Sheets-Sheet 1 21 z nz oz" Zoyd c (b/2225022 Aug, 18, 1959 L. c. JOHNSON 2,899,703

DOORHSTOP 7 Filed Jan. 13, 1955 2 Sheet's-SheetZ 4 H Ia f [22 dzzfozf .Zqgcz 6. (/022225022 2,899,703 DOOR s 'ror Loyd C. Johnson, Winnetka, Ill

Application January 13, 1955, Serial No. 481,608-

Claims. (CI. 16-86) This invention relates to builders hardware, and particularly to a door stop adapted to cooperate directly with a doorknob to stop the swing of a door toward a wall or other partition.

A form of door stop has been proposed which, instead of contacting the lower regions of the door as has been customary in the past, is designed to cooperate directly with the doorknob, since the doorknob is usually the part which projects the greatest distance from the surface of the door. In the proposed door stop, the part thereof which contacts the doorknob is comprised of a rubber block, cylinder or pad, the resilience of which is relied upon to absorb the momentum of the door without damaging the knob. When this type of door stop is used in conjunction with a doorknob having a centrally located button for operating a latch, it has been found that the button, rather than the knob itself, is contacted by the rubber and it i the button and its associated latch mechanism which is required to absorb the shock of arresting the swing of a door. The latch mechanism, however, is not built ruggedly enough to withstand this shock and as a result the use of a doorknob contacting type of door stop with a push button latch in the doorknob has resulted in damage to the latch mechanism.

It is accordingly a general object of this invention to provide an improved form of doorknob-contacting type of door stop which is particularly well suited for use with doorknobs equipped with outwardly extending push button latches.

Builders hardware, particularly door stops used in institutions such as schools, hospitals, mental and penal institutions, are frequently the targets of vandalism and theft. This is particularly true where the fasteners for the hardware are of the threaded type and are readily found.

As another object, this invention seeks to provide a door stop, or similar item of builders hardware, which is so constructed as to conceal the means by which it is fastened to a wall, partition or the like.

A more specific object of this invention is the provision of a door stop adapted to cooperate with a doorknob having a push button type of latch, the door stop requiring but a single screw for its attachment to a wallor partition, said screw being concealed from view but nevertheless be ing accessible to a carpenter or other person authorized to install or remove it and familiar with its construction.

Another specific object of this invention is to provide a door stop adapted to cooperate directly with a doorknob, said stop being economical to manufacture and easy to assemble and install. I

These and other objects of this invention will become apparent from the following detailed description when taken together with the accompanying drawings in which,

Fig. 1 is a front elevational view of a door stop made in accordance with this invention;

Fig. 2 is a side elevational view in section of the door stop of Fig. 1, shown attached to a fragment of a wall, the

section being taken along line 2-2 of Fig. l;

nited States Patent Fig. 3 is an exploded view of the door stop of Fig. 1 showing the components thereof;

Fig. 4 is a fragmentary side elevational view in section corresponding to the view shown in Fig. 2, showing the manner in which the fastening means for the stop is engaged by a suitable tool from the exterior;

Fig. 5 is a side elevational view of the door stop of Fig. l, partly in section showing the manner in which it cooperates with a doorknob having a centrally located, outwardly extending push button latch; and

Figs. 6, 7, and 8 are respectively, front elevational, side elevational in section and exploded views of a modification of the door stop of Fig. 1.

Referring now to the drawings for a detailed description of the invention and particularly to Fig. 5, there is shown a fragment of a door 10 on which has been mounted a doorknob 11 having an axially movable push button 12, the function of which is to operate a door latch (not shown). The construction of the push button 12, its associated latch and doorknob 11 is not a part of this invention and hence will not be described herein in detail. It may be observed, however, that push button 12 normally projects outwardly from the end surface 13 of doorknob 11 and, accordingly, if it is desired to employ a door stop which cooperates directly with the doorknob rather than with some other portion of the door, due regard must be given to the projecting latch button 12 to avoid damage tothe button and its associated latch.

' The door stop constructed in accordance with this invention is fastened to a wall 14 or other fixed partition or abutment against which door 10 is adapted to swing. The door stop is indicated generally at 15 and is comprised of a rigid frame 16 on which is centrally mounted a resilient deformable bumper member 17. The central portion of bumper 17 has a recess 18 in which push button 12 is adapted to be received when door 10 is swung to the right, as viewed in Fig. 5, to the point where knob 11 contacts, or is about to contact, bumper 17. Recess 18 is larger than button 12 to provide clearance between the button and bumper 17 when the end surface 13 of knob 11 contacts the outer surface 19 of bumper 17. Under normal operating conditions, therefore, movement of door 10 toward the right as viewed in Fig. 5 will be arrested by bumper 17 without said bumper, or any part of the door stop, actually contacting button 12. This assures maximum protection for the latch mechanism associated with button 12 and at the same time provides adequate means for arresting the swing of door 10.

The details of construction of door stop 15 are shown in Figs. 1 to 3, inclusive. Inasmuch as button 12 and knob 11 are generally made of cylindrical or spherical contour, recess 18 can likewise be made of cylindrical contour, or preferably of conical contour to facilitate formation in a mold having adequate draft. Frame 16 therefore may also be made of a circular or cylindrical contour, though other shapes may be used without departing from the spirit of this invention.

Bumper member 17 is preferably made of rubber or other elastomeric material having a durometer hardness which is such as to give the bumper adequate shock absorbing characteristics without unduly sacrificing strength to withstand repeated blows. The outer surface 20 of bumper 17 may therefore be conical from the knob contacting surface 19 outwardly, and then cylindrical as at 21 until it intersects the rear surface 22 of the bumper, said rear surface preferably being substantially flat. At the intersection of surfaces 20 and 21 is formed a peripheral groove 23 in which is adapted to be received an axially offset inwardly extending flange 24 of the frame 16.

The outer surface 25 of frame 16 may be made circular and concentric with the axis of bumper 17, saidsurface 25 being intersected by a radial surface 26 which extends inwardly toward flange 24 and is joined to said flange by a smoothly rounded fillet 27. Frame 16 is hollow and is closed off at its right hand end as viewed in Fig. 2 by a plate 28, the outer surface 29 of which is preferably disposed flush with the end surface 30 of frame 16; The inner surface of plate 28 is spaced from the rear surface 22 of bumper 17 by a plurality of bosses 32 formed adjacent the'inner periphery of frame 16. Plate 28 is secured to frame 16 by one or more fasteners such as screws 33 passing through countersunk openings 34 in plate 28 and into threaded openings 35 in bosses 32. It should be noted that openings 35 do not extend through bosses 32 and frame 16 to the front surface 26 thereof and hence they and the screws 33 are completely concealed from the exterior of the stop.

Bumper 17 is assembled with respect to frame 16 by pushing said bumper through the opening formed by flange 24 of frame 16. Conical surface 20 thus serves not only to enhance the appearance and increase the structural strength of the bumper member, but also to guide the bumper past flange 24, the bumper being resiliently deformed inwardly until flange 24 enters peripheral groove 23. Plate 28 is assembled on frame 16 after bumper 17 has been assembled on frame 16. It may be observed that disassembly of bumper 17 relative to frame 16 by moving the bumper to the right as viewed in Fig. 2 is impossible after plate 28 has been secured to frame 16. Disassembly of bumper 17 by its attempted movement to the left as viewed in Fig. 2 is rendered impossible by molding a rigid washer 36 into bumper 17 at a location therein such that washer 36 overlies, in part at least, flange 24 and preferably forms that wall of groove 23 which is disposed between flange 24 and plate 28. Any attempt to disassemble bumper 17 from frame 16 by pulling the bumper to the left therefore is rendered impossible without destroying the bumper.

The means for securing the door stop to wall 14 comprises a screw 37, the head 38 of which passes through an opening 39 located centrally of plate 28 and having the region 41] of the plate immediately adjacent opening 39 flared outwardly to receive head 38. The threaded portion of screw 37 may cooperate with a suitable threaded anchor 41 permanently secured to, or forming part of, wall 14. The head 38 of screw 37 is provided with a cruciform slot 42 (commonly known as a Phillips head) which is adapted to be engaged by a similarly formed screw driver 43.

The depth of recess 18 in bumper 17 is such as to leave a membrane or wall 44 across the bottom thereof. An access opening 45 is formed in the center of wall 44 in alignment with slot 42 in head 38. Opening 45, however, is smaller than head 38 to conceal the greater portion of the head and the nature of slot 42, except to the initiated. Screw driver 43, however, may be inserted in opening 45 and may expand said opening sufficiently to enable its head to engage slot 42 and operate screw 37.

Screw driver 43 is shown engaging head 38 in Fig. 4. in may be seen that any distortion of wall 44 caused by the expansion of opening 45 when the head of screw driver 43 is inserted therein may be accommodated by the space 46 provided between rear surface 22 of bumper 17 and the inner surface 31 of plate 28. After screw 37 has been tightened to the point where the door stop is firmly in place on wall 14, screw driver 43 may be withdrawn from opening 45 and the latter will contract to its normal size and thereafter conceal the presence of the screw from vandals, etc. Should screw 37 inadvertently be loose enough to permit the stop to be rotated, such rotation nevertheless will not necessarily result in a rotation of the screw 37 in a direction to back it out of anchor 41. The flared region 4% of plate 28 under such conditions would merely ride loosely either on the screw head 38 or on the main body of the screw 37 without necessarily developing sufficient friction to actually turn screw37 itself.

Where appearance is a prime factor, frame 16 may be made as a bronze casting, the exposed surfaces of which are suitably finished by grinding, buffing and polishing. It may also be made as a stamping or it may be molded from a shock resistant synthetic resin. The appearance of bumper 17 may likewise be enhanced by the use of suitable pigments and careful molding to provide the desired color and finish to the exposed surfaces thereof.

The modification shown in Figs, 6, 7 and 8 may be used where cost is more of a factor. The principal difference between this design and the one shownv in Figs. 1 to 5 is in the elimination of the metal frame 16 surrounding rubber bumper 17' and the substitution of an inexpensive hidden stamping therefor. The stop is thus comprised of a bumper 46 made of the same resilient deformable type of material as bumper 17 and formed with a central latch button receiving recess 47 having converging side walls and a substantially flat relatively thin inner wall 48 in which is formed a central access opening 49. Wall 48 and opening 49 correspond generally to wall 44 and access opening of Fig. 2.

The exterior surface 50 of bumper 46 is conical over the forward portion thereof and is substantially cylindrical over its rear portion 51-. The back 52 of the bumper has a recess 53 which is enlarged toward the front and then re-entrant at 54 to form a hook in radial cross section. A relatively heavy plate 55, preferably of stamped metal is inserted in recess 53, said plate extending into the enlarged forward portion thereof andhaving an axially turned flange 56 which extends into the re-entrant portion 54 of recess 53; It is contemplated that plate 55 will be formed separately and'then assembled relative to bumper 46 by stretching the hook portion of the bumper over flange 56 and the outer regions of the plate.

The central region 57 of plate 55 is punched outwardly toward the rear of the bumper and formed with an opening 58 through which extends the threaded shank of a flat headed machine screw 59, the head of which when installed is slightly below the inner surface 60 of inner wall 48. The space 61 formed between the screw head and wall is utilized to receive the distended material of the wall 48 immediately surrounding the opening 49. A second metal plate 62 having an external diameter substantially equal to the external diameter of the bumper rear portion 51 is inserted between the bumper and the wall 14 to provide a uniform surface for the back 52 of the bumper and also to act as a buffer between the bumper and wall in the event the bumper, through accident or attempted vandalism, became loose enough to rotate on bolt 59. An opening 63 is, of course, provided in plate 62 through which screw 59 passes.

The head of screw 59 has a cruciform slot 64 of the Phillips type, and the door stop of Figs. 6, 7 and 8 is se-' cured to wall 14 in the same manner as in door stop 15 of Figs. 1 to 5, i.e., by inserting the end of screw driver 43 into opening 49 and slot 64 and turning screw 59 until the stop is firmly in place. Axial pressure on plate 55 will clamp the hook portion of the end of the bumper to plate 62 and will render substantially impossible the removal of that portion from the plate.

It is understood that the foregoing description is merely illustrative of a preferred embodiment of the invention and that the scope of the invention therefore is not to be limited thereto but is to be determined by the appended claims.

I claim:

1. A door stop comprising a rigid circular frame having a front wall with a circular opening therein and an open back, a resilient deformable bumper extending through the circular opening and having a peripheral groove adapted to receive therein the wall regions adjacent the opening, a plate extending across the back of the frame, and a rigid reinforcing ring secured to the portion of the bumper disposed in the space between the front wall and the plate and having an outside diameter greater than the diameter of the circular opening in the front wall and means for securing the plate to a wall or the like.

2. A door stop comprising a rigid frame having a front wall with an opening therein and an open back, a resilient deformable bumper extending through the opening in the front Wall and having a peripheral groove adapted to receive therein the wall region adjacent the opening, a plate extending across the back of the frame and spaced from the bumper, said bumper having a recess therein extending toward the plate and terminating in a flexible membrane, a threaded fastener for securing the stop to a wall, said plate having an opening therein for the reception of said fastener and said membrane having an opening in axial alignment with the fastener, one end of the said fastener being disposed behind and in spaced relation to the membrane and the opening in the membrane being of lesser area than the area of the said end of the fastener, whereby partly to conceal said end of the fastener.

3. A door stop as described in claim 2, said frame having a plurality of threaded recesses extending from the back of the frame toward the front wall, and fasteners extending through the plate from the back of the stop and into the threaded recesses for securing the plate to the frame.

4. A door stop as described in claim 2, said fastener comprising a screw having its head disposed between the plate and the membrane, said frame having a plurality of threaded recesses extending from the back of the frame toward the front wall, and fasteners extending through the plate from the back of the stop and into the threaded recesses for securing the plate to the frame.

5. A door stop as described in claim 2, and a rigid ring embedded in the bumper and overlying a portion of the front wall and disposed between the front wall and the plate.

6. A door stop comprising a rigid circular frame having a front wall having an axially ofiset annular flange defining a concentric circular opening therein and an open back, a frusto-conical bumper of resilient deformable material extending through the opening and having a peripheral groove to receive therein the annular flange, a rigid washer defining one wall of the groove and extending radially inwardly of the bottom of the groove into the bumper, a plate extending across the back of the frame and spaced from the bumper, said frame having a plurality of threaded recesses extending from the back of the frame toward the front wall, fasteners extending through the plate from the back of the stop and into the threaded recesses for securing the plate to the frame, said bumper having a recess therein extending toward the plate and terminating in a flexible membrane, a screw,

said plate having an opening therein for the reception of the screw with the head of the screw disposed between the membrane and plate, and said membrane having an opening in axial alignment with the screw and of smaller diameter than the diameter of the screw head, said membrane opening being distortable to receive a screw driver or the like for turning the screw.

7. A door stop adapted to be secured to a wall comprising a [resilient deformable bumper having a recess opening on the front of the stop and extending toward the back of the stop and having an annular recess near its rear end, a plate extending across the back of the bumper and having means thereon extending into the annular recess so as to be locked therein, said plate and the bumper at the bottom of the recess in the bumper having substantially aligned openings therein, a screw extending through the opening in the plate and adapted to be secured to the wall, the opening in the bumper being smaller than the head of the screw and being distendable to receive a screw driver.

8. A door stop adapted to be secured to a wall comprising a resilient deformable bumper having a recess opening on the front of the stop and extending toward the back of the stop and having an annular recess near its rear end, a plate extending across the back of the bumper and into said annular recess so as to be locked therein, said plate and the bumper at the bottom of the recess in the bumper having substantially aligned openings therein, a screw extending through the opening in the plate and adapted to be secured to the wall, the opening in the bumper being smaller than the head of the screw and being distendable to receive a screw driver.

9. A door stop as described in claim 8, a second plate spaced from the first plate, said bumper extending into the said space and being clamped therebetween when the screw is made fast.

10. A door stop as described in claim 8, said annular recess extending radially outwardly and then axially, and the plate having an axially extending flange adapted to be received in the axially extending portion of the annular recess, a second plate spaced from the first plate and overlying the flange on the first plate, said bumper extending into the said space and being clamped therebe' tween when the screw is made fast.

References Cited in the file of this patent UNITED STATES PATENTS 1,163,463 Rogers Dec. 7, 1915 1,563,876 Smith Dec. 1, 1925 2,149,375 Wiebe Mar. 7, 1939 2,182,611 Covert Dec. 5, 1939 

